Fundamental issues both within and beyond biology are how the brain develops and how its interactions with the environment influence behavior. The Developmental Disabilities Research Center (DDRC) at the University of Massachusetts Medical School (UMMS) addresses these issues through wide-ranging programs of research on typical and atypical development, which include biomedical, biobehavioral, behavioral, and social science dimensions. Specific focus areas include developmental neuroscience, genetics of neurodevelopmental disorders, sensory systems and information processing, behavioral and cognitive neuroscience, cognitive psychology and behavior analysis, and social process and policy analysis. The DDRC and its companion University Center for Excellence in Developmental Disabilities (UCEDD) also train professionals for careers in research and service to people with disabilities and their families. Research interests of the UMMS DDRC include (1) understanding biological processes that occur during development of the nervous system;(2) characterizing molecular defects in genetic disorders which affect the nervous system;(3) establishing the genetic basis of neurodevelopmental disorders, along with potentially related neuropsychiatric and neurodegenerative disorders;(4) identifying brain regions and functional systems that may be involved in MRDD;(5) advancing knowledge of fundamental processes involved in learning, perception, language, and cognition;(6) applying the latter knowledge to improve the educational opportunities for persons with MRDD, and (7) understanding social processes and social policy implications relevant to persons with MRDD and their families. This revised application for MRDDRC funding encompasses a number of new interdisciplinary collaborations among UMMS faculty and programs. Four core units are proposed to encourage further collaborations relevant to the missions of the DDRC and NICHD. The core units are: Administration, Neuroscience Integration and Support, Scientific and Technical Information Services, and Clinical and Translational Research Support. Each core unit features equipment, facilities, and/or problem-solving capability, and each gives quality, cost-effective service to numerous PHS-funded projects. The collective operations of the cores will both enhance existing MRDD research, and stimulate new interdisciplinary and translational research in MRDD at UMMS and its affiliated institutions.